Which of the following events could NOT be caused by a population bottleneck?

Loss of alleles

Increased population size

Reduction in genetic variability

Changes in allele frequency

The event that could not be caused by a population bottleneck is increased population size.

Explanation:

Population bottleneck (genetic bottleneck) is a phenomenon that causes a sharp reduction in population size. It is caused by various factors like environmental disasters such as disease, famines, earthquakes, floods, etc or human activities like hunting, genocide, destruction of habitat, etc. These factors reduce the genetic variation in a population and cause smaller genetic diversity in a smaller population. This causes a change in allele frequency (genetic drift) and it leads to loss of alleles. The effects of genetic drift are stronger in smaller populations than large ones. The small population size increases the chances of inbreeding, accumulation of harmful mutations and genetic homogeneity which leads to inbreeding depression.

An example of a population bottleneck is Cheetahs, which suffers a reduction in genetic diversity during their bottleneck. As a result, they have problems in their reproduction and are highly susceptible to diseases.